Figure 46.
Sector structure of the solar magnetic field. The data are for
December 1963 to February 1964. The direction of the average
experimental interplanetary magnetic field during three-hour
intervals is denoted by plus signals (away from the sun) and minus
signs (toward the sun). Parentheses around a plus or minus sign
indicate that the field direction fluctuated significantly. The
solid lines represent magnetic field lines at sector boundaries.
Alois W. Schardt and Albert G. Opp in Significant Achievements in Space
Science, 1965, NASA SP-136 (1967),
p.42.